(1). PDGF/VEGF targeting in treating ocular neovascular diseases. Neovascular complication in the eye is the major cause of blindness in the old population and the Western society. Many angiogenesis inhibitors have been tested for treating such diseases, and beneficial effects have been demonstrated. Yet, the progression of such pathologies cannot be halted or reversed. Studies characterizing new molecules playing important roles in ocular neovascularization are therefore awaited. Ongoing work in our unit is investigating the angiogenic activity of the PDGFs/VEGFs in ocular neovascularization and the potential of PDGF/VEGF targeting in treating ocular vascular diseases. (2). Neuroprotection by growth factors in retinal neurodegenerative diseases. Neurodegeneration occurs in many types of ocular diseases. Numerous factors contribute to such diseases and there is currently no general treatment effective for all forms of retinal degeneration. Neuroprotection as achieved by neurotrophic/survival factors has emerged to be one general strategy for the treatment of such pathologies. However, the number of such neuroprotective factors is still limited. We are currently using multiple approaches including protein delivery, gene and cell therapy, normal and transgenic mice, in combination with other loss-of-function studies to investigate the neuroprotective effect of several growth factors in treating retinal neurodegenerative diseases. (3). Effect of PDGFs/VEGFs on retinal stem cells and retinal development. Cell therapy using eye stem cells is one of the most promising therapeutic approaches to treat retinal neurodegenerative diseases. However, it is yet not well understood how the eye stem cells are regulated. A better understanding into this aspect is warranted. We are currently using multiple approaches, such as protein/gene delivery and transgenic mice for gain of function studies, and RNAi/neutralizing antibodies and the gene deficient mice for loss of function studies, to investigate the role of the PDGFs/VEGFs in ocular stem cell proliferation/differentiation and retinal development.